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Annotation of OpenXM_contrib/gmp/printf/snprntffuns.c, Revision 1.1

1.1     ! ohara       1: /* __gmp_snprintf_funs -- support for gmp_snprintf and gmp_vsnprintf.
        !             2:
        !             3:    THE FUNCTIONS IN THIS FILE ARE FOR INTERNAL USE ONLY.  THEY'RE ALMOST
        !             4:    CERTAIN TO BE SUBJECT TO INCOMPATIBLE CHANGES OR DISAPPEAR COMPLETELY IN
        !             5:    FUTURE GNU MP RELEASES.
        !             6:
        !             7: Copyright 2001, 2002 Free Software Foundation, Inc.
        !             8:
        !             9: This file is part of the GNU MP Library.
        !            10:
        !            11: The GNU MP Library is free software; you can redistribute it and/or modify
        !            12: it under the terms of the GNU Lesser General Public License as published by
        !            13: the Free Software Foundation; either version 2.1 of the License, or (at your
        !            14: option) any later version.
        !            15:
        !            16: The GNU MP Library is distributed in the hope that it will be useful, but
        !            17: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
        !            18: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
        !            19: License for more details.
        !            20:
        !            21: You should have received a copy of the GNU Lesser General Public License
        !            22: along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
        !            23: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
        !            24: MA 02111-1307, USA. */
        !            25:
        !            26: #include "config.h"
        !            27:
        !            28: #if HAVE_STDARG
        !            29: #include <stdarg.h>
        !            30: #else
        !            31: #include <varargs.h>
        !            32: #endif
        !            33:
        !            34: #include <stdio.h>
        !            35: #include <string.h>
        !            36:
        !            37: #include "gmp.h"
        !            38: #include "gmp-impl.h"
        !            39:
        !            40:
        !            41: #if ! HAVE_VSNPRINTF
        !            42: #define vsnprintf  __gmp_replacement_vsnprintf
        !            43: #endif
        !            44:
        !            45:
        !            46: /* glibc 2.0.x vsnprintf returns either -1 or size-1 for an overflow, with
        !            47:    no indication how big the output would have been.  It's necessary to
        !            48:    re-run to determine that size.
        !            49:
        !            50:    "size-1" would mean sucess from a C99 vsnprintf, and the re-run is
        !            51:    unnecessary in this case, but we don't bother to try to detect what sort
        !            52:    of vsnprintf we've got.  size-1 should occur rarely in normal
        !            53:    circumstances.
        !            54:
        !            55:    vsnprintf might trash it's given ap (it does for instance in glibc 2.1.3
        !            56:    on powerpc), so copy it in case we need to use it to probe for the size
        !            57:    output that would have been produced.  Note there's no need to preserve
        !            58:    it for our callers, just for ourselves.  */
        !            59:
        !            60: static int
        !            61: gmp_snprintf_format (struct gmp_snprintf_t *d, const char *fmt,
        !            62:                      va_list orig_ap)
        !            63: {
        !            64:   int      ret, step, alloc, avail;
        !            65:   va_list  ap;
        !            66:   char     *p;
        !            67:
        !            68:   ASSERT (d->size >= 0);
        !            69:
        !            70:   avail = d->size;
        !            71:   if (avail > 1)
        !            72:     {
        !            73:       va_copy (ap, orig_ap);
        !            74:       ret = vsnprintf (d->buf, avail, fmt, ap);
        !            75:       if (ret == -1)
        !            76:         {
        !            77:           ASSERT (strlen (d->buf) == avail-1);
        !            78:           ret = avail-1;
        !            79:         }
        !            80:
        !            81:       step = MIN (ret, avail-1);
        !            82:       d->size -= step;
        !            83:       d->buf += step;
        !            84:
        !            85:       if (ret != avail-1)
        !            86:         return ret;
        !            87:
        !            88:       /* probably glibc 2.0.x truncated output, probe for actual size */
        !            89:       alloc = MAX (128, ret);
        !            90:     }
        !            91:   else
        !            92:     {
        !            93:       /* no space to write anything, just probe for size */
        !            94:       alloc = 128;
        !            95:     }
        !            96:
        !            97:   do
        !            98:     {
        !            99:       alloc *= 2;
        !           100:       p = __GMP_ALLOCATE_FUNC_TYPE (alloc, char);
        !           101:       va_copy (ap, orig_ap);
        !           102:       ret = vsnprintf (p, alloc, fmt, ap);
        !           103:       (*__gmp_free_func) (p, alloc);
        !           104:     }
        !           105:   while (ret == alloc-1 || ret == -1);
        !           106:
        !           107:   return ret;
        !           108: }
        !           109:
        !           110: static int
        !           111: gmp_snprintf_memory (struct gmp_snprintf_t *d, const char *str, size_t len)
        !           112: {
        !           113:   size_t n;
        !           114:
        !           115:   ASSERT (d->size >= 0);
        !           116:
        !           117:   if (d->size > 1)
        !           118:     {
        !           119:       n = MIN (d->size-1, len);
        !           120:       memcpy (d->buf, str, n);
        !           121:       d->buf += n;
        !           122:       d->size -= n;
        !           123:     }
        !           124:   return len;
        !           125: }
        !           126:
        !           127: static int
        !           128: gmp_snprintf_reps (struct gmp_snprintf_t *d, int c, int reps)
        !           129: {
        !           130:   size_t n;
        !           131:
        !           132:   ASSERT (reps >= 0);
        !           133:   ASSERT (d->size >= 0);
        !           134:
        !           135:   if (d->size > 1)
        !           136:     {
        !           137:       n = MIN (d->size-1, reps);
        !           138:       memset (d->buf, c, n);
        !           139:       d->buf += n;
        !           140:       d->size -= n;
        !           141:     }
        !           142:   return reps;
        !           143: }
        !           144:
        !           145: static int
        !           146: gmp_snprintf_final (struct gmp_snprintf_t *d)
        !           147: {
        !           148:   if (d->size >= 1)
        !           149:     d->buf[0] = '\0';
        !           150:   return 0;
        !           151: }
        !           152:
        !           153: const struct doprnt_funs_t  __gmp_snprintf_funs = {
        !           154:   (doprnt_format_t) gmp_snprintf_format,
        !           155:   (doprnt_memory_t) gmp_snprintf_memory,
        !           156:   (doprnt_reps_t)   gmp_snprintf_reps,
        !           157:   (doprnt_final_t)  gmp_snprintf_final
        !           158: };